Thanks for dropping by the Community, @sherry27.

In QuickBooks Online (QBO), to enlarge the print on checks, you can use the scale on the Print settings to adjust them. Here's how to do it:

1. Open the specific check, then click the Print check option at the bottom.
2. Select the Print icon at the top right to open the settings.
3. Tick the More settings drop-down.
4. Choose Custom in the Scale field, then adjust the size by clicking the Up or Down arrow.
5. Once done, hit Print to complete. 

You can also print partial pages and voucher checks in QBO, visit this article for more information: Print checks.

Please leave a comment below if you have any additional questions or concerns. I'm always here to answer them. Have a great day!